function C = jacobian_f_unknown_landmark(x0, landmark_idx_into_state)


% your code here
% your code here

%l = landmark_idx_into_state;

%landmark_ne_estimate = x(3 + (l-1)*2 + 1 : 3 + (l-1)*2 + 2);

eps = 1e-3;

for j=1:numel(x0)
   x = x0;
   x(j)=x0(j)+eps;
   y2=f_unknown_landmark(x, landmark_idx_into_state);
   x(j)=x0(j)-eps;
   y1=f_unknown_landmark(x, landmark_idx_into_state);
   
   C(:,j)=(y2-y1)/(2*eps);
end